Air-motor



(No Model.)

W. H. KNIGHT. AIR MOTOR.

Patented Sept. 29, 1896.

ATTORNEYS UNITED STAT \VALTER II. KNIGHT, OF NEIV BRIGHTON, NEW'YORK.

AIR-MOTOR.

SPECIFICATION forming part of Letters Patent No. 568,354, dated September 29, 1896.

A li ation filed December 30, 1895. Serial No. 573,824. (No model.)

To all whom it may concern:

Be it known that I, \VALTER II. KNIGHT, a citizen of the United States, residing at New Brighton, Richmond county, State of New York, have invented a new and useful Improvement in Air-\Iotors, of which the following is a specification.

My invention relates to reciprocating niotors, and has for its object the provision of means for operating the valve mechanism of such motors with compressed fluid in lieu of eccentrics, cams, or the like.

My invention further relates to means for operating cut-oft valves in connection with the main admission and exhaust valves by means of compressed fluid.

My invention further relates to means for reversing motors operated by fluid-actuated valves.

The accompanying drawing represents in partly-sectional plan view a double -acting duplex motor embodying myinvention.

A A are cylinders; B B, pistons; O O, piston-rods; D D, cross-heads; E E, connectingrods, and F F cranks of ordinary construction, the two cranks being set at an angular distance apart of ninety degrees.

G g is the main valve, which is of the piston type and is adapted to be operated by the air compressed by the main piston at each end of the stroke, operating through ports H h.

I care the supply and exhaust ports. Compression takes place immediately after the main piston has passed over and closed the exhaust-port in its passage toward the end of the cylinder. The air thus compressed, passing through ports H it, throws the main valve G g so as to open the port justcovered by the piston to the live-air supply in the air-chest J, and throw the port at the other end of the cylinder in communication with the atmosphere through passages Z. The main valve remains in this position until the piston reaches the other end of the cylinder, when it is thrown backward by the compression taking place at that end.

K K are cut-oft valves riding on the main valve and operated, together with the main valve, by the compressed air at the end of the stroke, as just described, but thrown back when the piston 13 has moved far enough to uncover cut-off ports K 7c.' These cut-off ports admit compressed air from the cylinder to the inner face of the cut-off valve, which is made larger than that face upon which the compression-pressu re ope'rated,the difference in area being suflicient to insure the movement of the cut-off. The cut-off ports are supposed to be located at that part of the stroke which will give the best average results.

There may be more than one set of cut-off ports to give different degrees of expansion, as, for instance, K 70. In such case a manual valve L, operated by rods L, could be used to shut off one set of ports and simultaneously open the other set, the ports Z in the valve L being placed at proper intervals to accomplish this result. The valve L can in one position close all of such cut-oft passages, so as to prevent the valves K K from closing, thereby causing the engine to take pressure full stroke. By this means one cut-off may be used forgiving maximum economy and the other cutoff may be used for starting or giving maximum'capacity. Itwill-be seen that after the cut-off valve is thrown back when the piston arrives at the cut-off point it remains in that position, and at the end of the stroke the main valve is thrown back against it, bringing both Valvesback to their starting position.

In order. to reverse a motor of this kind, it is simply necessaryto throw the valves into the opposite positionlfrom which'they are standing. To do this, I provide a reversingvalve M operated by reversing lever N, which, when thrown over by rod 01, admits air from the air-chest J to a part 0 of the main valve that is provided with ports 0, designed to allow the air to flow to that end of the valve, which will throw it in the opposite direction from which it is standing. Upon being so thrown over the ports 0 will arrange themselves in position to throw the valve back but in the meantime the operator has bya further movement of the lever N thrown the valve M so as to shut off further admission of air to the ports 0. The air flowing through valve M and ports 0 is led by passages'P to chamber Q and operates therein upon a face of the cut-off valve, which is larger in area than the end faces upon which the compression-pressure operates, this dif ference of area being such as to insure the throwing over of the valve irrespective of any pressure that may exist in the cylinder or in ports II 7L.

The machine is started or stopped by means of throttle valve T. The locating of the cranks ninety degrees apart insures the following of the piston to the end of the stroke, notwithstanding the compression which takes place at that point.

Having thus described my invention, the following is what I claim as new therein and desire to secure by Letters Patent:

1. The combination of the cylinder, and the piston adapted to compress fluid in the end of the cylinder, with the main valve, and cutoff valves controlling the main valve and operated by the fluid compressed in the end of the cylinder.

2. The combination of the cylinder and piston with ports so arranged as to compress contents of the cylinder at the end of the stroke with a valve controlling admission and exhaust ports of such cylinder and operated by said pressure.

3. The combination of two cylinders with their pistons, piston-rods, connecting-rods and cranks, with the cranks set substantially at right angles with ports a each end of the cylinders so located as to give compression at the end of the stroke, and the valve for each cylinder controlling the admission and exhaust from the cylinders and passages leading from the ends of the cylinders to the valvechambers so that the said valves may operate solely by the pressure due to compression.

l. The combination with the cylinder and piston of a valve operated by compression caused at each end of the cylinder by the piston and a cut-off valve operated by the pressure in the cylinder and through a port exposed by the piston after it has traveled a predetermined part of the stroke.

5. In a fluid-pressure motor the combination of the cylinder and piston moving therein, a main valve controlling the admission and exhaust of the fluid to and from the cylinder and cut-cit valve for each end, and ports leading from the ends of the cylinder to the cut-off-valve chambers so that such valves may be operated by compression of the fluid at the end of the stroke, the main .valve being acted upon directly by the cutfrom the cylinder to the cut-off-valve chambers through which cylinder pressure can be admitted to the said valve-chambers when the piston reaches a predetermined point or points of its stroke to operate the cut-oft valves and close the admission-ports.

7. In a fluid-pressure motor the combination with the cylinder and piston of a fluid-actuated cut-off valve, and the main valve operated by the cut-off valve, of admission and exhaust ports opened and closed by said valves, passages leading from the ends of the cylinder to the face of the cut-off valves of a given area, cut-off ports extending from cutoff points in the cylinder to the opposite ends of the cut-off Valves which ends have greater area than the aforesaid ends of given area.

8. In a fluid-pressure motor the combination of the cylinder and piston with a main valve and cut-off valves actuated by the fluidpressure, with cut-off passages leading from each cut-oi'f-valve chamber to points in. the cylinder corresponding to positions of maxi mum economy cut-off, and maximum capacity cut-off and means for closing one set of such passages or both.

9. In a fluid-pressure motor the combination of the cylinder and piston with fluidaetuated valves and reversing mechanism consisting of a manual valve and automatic valve, the former admitting fluid under pressure and the latter directing the fluid so as to reverse the valves and consequently the direction of the machine.

WALTER II. KNIGHT. lVitnesses:

M. V. Bincoon, II. E. KNIGHT. 

